Podcast
Questions and Answers
During meiosis, homologous pairs can exchange pieces of DNA after they synapse?
During meiosis, homologous pairs can exchange pieces of DNA after they synapse?
True
What does mitosis involve?
What does mitosis involve?
a single cell division, and results in two diploid cells
DNA replication occurs prior to both meiosis and mitosis?
DNA replication occurs prior to both meiosis and mitosis?
True
What is the normal chromosome number in a human cell?
What is the normal chromosome number in a human cell?
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What does completion of meiosis produce?
What does completion of meiosis produce?
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How many cells are formed in meiosis?
How many cells are formed in meiosis?
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What is known as the differing orientations of chromosomes along the cell equator during metaphase I?
What is known as the differing orientations of chromosomes along the cell equator during metaphase I?
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Meiosis II is identical to mitosis?
Meiosis II is identical to mitosis?
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During meiosis, DNA must replicate twice?
During meiosis, DNA must replicate twice?
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What is the exchange of DNA between adjacent homologous chromatids known as?
What is the exchange of DNA between adjacent homologous chromatids known as?
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What events occur during prophase I?
What events occur during prophase I?
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How many bivalents are formed in a cell with 20 chromosomes at the beginning of meiosis I?
How many bivalents are formed in a cell with 20 chromosomes at the beginning of meiosis I?
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What events occur during anaphase I?
What events occur during anaphase I?
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At the end of meiosis I, there are two haploid cells, each with two sister chromatids per chromosome?
At the end of meiosis I, there are two haploid cells, each with two sister chromatids per chromosome?
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By the end of which phase is the spindle apparatus fully formed?
By the end of which phase is the spindle apparatus fully formed?
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Separation of ________ occurs in anaphase II of meiosis.
Separation of ________ occurs in anaphase II of meiosis.
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At the end of meiosis II, how many cells are formed?
At the end of meiosis II, how many cells are formed?
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Replication of chromosomes occurs between meiosis I and meiosis II?
Replication of chromosomes occurs between meiosis I and meiosis II?
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In animal cells, cell division is accomplished by the formation of a cleavage furrow?
In animal cells, cell division is accomplished by the formation of a cleavage furrow?
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What is a tetrad made up of?
What is a tetrad made up of?
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Crossing over occurs during prophase I of meiosis?
Crossing over occurs during prophase I of meiosis?
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Crossing over allows the reassortment of linked genes?
Crossing over allows the reassortment of linked genes?
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In meiosis I, the homologous pairs of chromosomes are separated when the cell divides?
In meiosis I, the homologous pairs of chromosomes are separated when the cell divides?
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What are homologous chromosomes?
What are homologous chromosomes?
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Match the following terms with their definitions:
Match the following terms with their definitions:
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How many phenotypes are possible for the dimples trait with strict dominant-recessive inheritance?
How many phenotypes are possible for the dimples trait with strict dominant-recessive inheritance?
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How many phenotypes are possible for the sickle-cell trait that exhibits incomplete dominance?
How many phenotypes are possible for the sickle-cell trait that exhibits incomplete dominance?
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Study Notes
Meiosis Overview
- Meiosis involves two cell divisions resulting in four haploid daughter cells.
- It is essential for sexual reproduction, producing gametes with half the normal chromosome number.
Meiosis Stages
-
Prophase I:
- Nuclear envelope breaks down.
- Chromosomes condense.
- Centrosomes move to opposite poles.
- Crossing over occurs, allowing genetic material exchange between homologous chromosomes.
-
Metaphase I:
- Homologous chromosome pairs align along the cell equator.
- Independent assortment creates varied gametes.
-
Anaphase I:
- Homologous chromosomes separate and move to opposite poles.
-
Telophase I:
- Two daughter cells form; each cell is haploid but contains two sister chromatids per chromosome.
Meiosis II
- Similar to mitosis, involving separation of sister chromatids.
-
Prophase II:
- Spindle apparatus forms.
-
Anaphase II:
- Sister chromatids separate and move to opposite poles.
-
Telophase II:
- Four haploid cells result, each with chromosomes consisting of a single chromatid.
Key Concepts
- Homologous chromosomes: Chromosomes with the same genetic information but may carry different alleles.
- Tetrad: Composed of two homologous chromosomes, each with two sister chromatids, formed during Prophase I.
- Crossing over: Exchange of genetic material between adjacent homologous chromatids enhances genetic variability.
Genetic Principles
- Gene: The functional unit of heredity consisting of DNA.
- Allele: Variants of a gene located at the same position on homologous chromosomes.
- Genome: The complete set of genes in one individual.
-
Inheritability:
- Dominant-recessive traits (e.g., dimples) result in two phenotypes.
- Incomplete dominance (e.g., sickle-cell trait) allows three phenotypes.
Important Facts
- Human cells typically contain 46 chromosomes (23 pairs).
- DNA replication occurs before meiosis I, not between meiosis I and II.
- At the end of meiosis II, each of the four haploid cells has a distinct combination of genetic material due to crossing over and independent assortment.
Studying That Suits You
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Description
Test your knowledge of meiosis with these flashcards. This set includes true or false questions and definitions related to meiotic processes and their differences from mitosis. Ideal for studying biology concepts related to cell division.
